Question

I posted another question which was resolved perfectly however I now need to apply the same code I was given to a different piece of MySQL code.

What I have is

SELECT value, COUNT(*) AS 'num' 
FROM table_c 
WHERE table_c_id IN (9, 17, 25)
GROUP BY value

What I would like to do now is only show the results if they have been entered on the current date?

The current code snippet I have for checking the current date, which works great is (the date is in unixtime format)

( xxxxxxxxxxxxxx and curdate() = date( from_unixtime( b.crm_date_time_column ) ) )

The problem I have with query this is the date column is located in a totally different table, table_a.

How do I write the MySQL to check table_a for the date and apply the existing date SQL I have?

This is a MySQL database.

Any help will be gratefully received! This is way over my head!

Answer 1

You’ll want to first JOIN the other table onto the first using related columns (I’m assuming id in the other table is related to table_c_id).

And as I had stated in my answer to your previous question, you’re better off making the comparison on the bare datetime column so that the query remains sargable(i.e. able to utilize indexes):

SELECT     a.value
FROM       table_c a
INNER JOIN table_a b ON a.table_c_id = b.id
WHERE      a.table_c_id IN (9,17,25) AND
           b.crm_date_time_column >= UNIX_TIMESTAMP(CURDATE())
GROUP BY   a.value 

This assumes the crm_date_time_column will never contain times which are in the future (e.g. tomorrow, next month, etc.), but if it can, you would just add:

AND b.crm_date_time_column < UNIX_TIMESTAMP(CURDATE() + INTERVAL 1 DAY)

as another condition in the WHERE clause.